My question relates to the required PIN changes to support the use of the two shields concurrently. Can I please get some information of which PINs need to be remapped on each of the VNH5019 Motor Driver Shield boards?

It appears that lines 6 through 32 of the DualVNH5019MotorShieldMod3.cpp file in that library list the default pins used by the motor shields for the library, but it also seems like it is possible to use your own mappings as well.